<!DOCTYPE html>
<html lang="zh-CN">
  <head>
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <!-- 上述3个meta标签*必须*放在最前面，任何其他内容都*必须*跟随其后！ -->
    <title>Bootstrap 101 Template</title>

    <!-- Bootstrap -->
    <link href="css/bootstrap.min.css" rel="stylesheet">

    <!-- HTML5 shim and Respond.js for IE8 support of HTML5 elements and media queries -->
    <!-- WARNING: Respond.js doesn't work if you view the page via file:// -->
    <!--[if lt IE 9]>
      <script src="https://cdn.bootcss.com/html5shiv/3.7.3/html5shiv.min.js"></script>
      <script src="https://cdn.bootcss.com/respond.js/1.4.2/respond.min.js"></script>
    <![endif]-->
  </head>
  <body>
    <div class="container">
       <div class="row">
          <h1><b>你好，世界！</b></h1>
          <div class="col-md-6">.第一个栅格</div>
          <div class="col-md-6">.第二个栅格</div>
          <!--<div class="col-md-4">.col-md-4</div>-->
        </div>
        <div class="row">
          <h1><b>你好，世界！</b></h1>
          <div class="col-md-6">.第三个栅格</div>
          <div class="col-md-6">.第四个栅格</div>
          <!--<div class="col-md-4">.col-md-4</div>-->
        </div>
        <div class="row">
          <h1><b>你好，世界！</b></h1>
          <div class="col-md-6">.第五个栅格
          <div class="row">
          <h1><b>你好，世界！</b></h1>
          <div class="col-md-4">.第1个栅格</div>
          <div class="col-md-4">.第2个栅格</div>
          <div class="col-md-4">.第3个栅格</div>
          </div>
          </div>
          <div class="col-md-6">.第六个栅格</div>
          <!--<div class="col-md-4">.col-md-4</div>-->
        </div>
    </div> 
    <table class="table table-bordered">
      <tr><td>12345</td><td>12345</td><td>12345</td><td>12345</td><td>12345</td></tr>
      <tr><td>12345</td><td>12345</td><td>12345</td><td>12345</td><td>12345</td></tr>
      <tr><td>12345</td><td>12345</td><td>12345</td><td>12345</td><td>12345</td></tr>
      <tr><td>12345</td><td>12345</td><td>12345</td><td>12345</td><td>12345</td></tr>
    </table>
    <form>
  <div class="form-group">
    <label for="exampleInputEmail1">请输入邮箱</label>
    <input type="email" class="form-control" id="exampleInputEmail1" placeholder="邮箱">
  </div>
  <div class="form-group">
    <label for="exampleInputPassword1">密码</label>
    <input type="password" class="form-control" id="exampleInputPassword1" placeholder="密码只能为字母和数字组合">
  </div>
  <div class="form-group">
    <label for="exampleInputFile">File input</label>
    <input type="file" id="exampleInputFile">
    <p class="help-block">Example block-level help text here.</p>
  </div>
  <button type="submit" class="btn btn-default">登录</button>
</form>
<div class="container">
    
    <div class="row">

    <div class="col-md-4 col-md-offset-4">
    <h1>登录界面</h1>
    <form>
  <div class="form-group">
    <label for="exampleInputEmail1">请输入邮箱</label>
    <input type="email" class="form-control" id="exampleInputEmail1" placeholder="邮箱">
  </div>
  <div class="form-group">
    <label for="exampleInputPassword1">密码</label>
    <input type="password" class="form-control" id="exampleInputPassword1" placeholder="密码只能为字母和数字组合">
  </div>
  <!--<button type="submit" class="btn btn-default">登录</button>-->
  <p>
  <button type="button" class="btn btn-primary btn-lg btn-block">登录</button>
</p>
</form>
</div>
</div>   
</div>
    
    <!-- jQuery (necessary for Bootstrap's JavaScript plugins) -->
    <script src="https://cdn.bootcss.com/jquery/1.12.4/jquery.min.js"></script>
    <!-- Include all compiled plugins (below), or include individual files as needed -->
    <script src="js/bootstrap.min.js"></script>
  </body>
</html>